Industrial locations such as chemical, petrochemical, oilfields, coalmines and the like often are scattered or stocked with gases, dust or chemicals that are inflammable, easily exploded or oxidized, or corrosive. Hence lamps used at those locations must be explosion-proof to avoid incidents of gas explosion or chemical explosion caused by sparks that might be generated by worn out or malfunctioned non explosion-proof lamps.
The wiring of conventional explosion-proof lamps generally has to use an extra explosion-proof cable gland tightly compacting with the cable to enhance air tightness. When connecting one or more explosion-proof lamps in series, an additional explosion-proof wiring box is needed to wire and install the explosion-proof lamps.
Hence installation of the conventional explosion-proof lamps might require extra wiring or using the explosion-proof cable gland and the wiring box. In order to improve explosion-proof effect the conventional explosion-proof cable gland often are made bulkier in size. As a result, the production cost of the cable gland is higher, installation with the explosion-proof lamp is more inconvenient, and applicability and versatility of the lamp sets are impaired. All this shows that there is still room for improvement.